Effect of KIT gene polymorphism on the reproductive ability of mini pigs

Fertility rate is crucial for agriculture and biomedical research using animal models, including mini pigs, which are valued for their physiological similarities to humans. However, reproductive challenges like low fertility and small litter sizes hinder their breeding and research utility. The study evaluated the relationship between coat color and two reproductive characteristics, litter size (prolificacy) and piglet birth weight (piglet weight), in laboratory mini pigs. The study aimed to determine whether the observed increase in fertility in white sows leads to a decrease in the individual weight of piglets or whether the color of the coat directly affects these reproductive characteristics. The study used a breeding group of laboratory mini pigs from the Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences to analyze data on 2,484 piglets born between 2013 and 2020. White sows and white sows with black spots showed significantly higher fertility, with 1-2 piglets more in the litter compared to colored sows (agouti, black, and spotted). However, piglets from white sows and white sows with black spots had significantly lower (about 30 g) birth weights than piglets from colored sows. The analysis showed that higher fertility in white sows may be due to genetic factors related to the KIT gene, which regulates pigmentation. The results support the hypothesis that coat color, especially in white sows, affects reproductive traits due to genetic mechanisms.